Container closure



Aug. 2, 1966 A. K. GRIMSLEY CONTAINER CLOSURE Filed May 14, 1964INVENTOR.

14E V/D AJELLSE/V @P/MSLE) United States Patent 3,263,851 CONTAINERCLOSURE Arvid Kjellsen Grimsley, Rockaway, N.J., assignor to AmericanCan Company, New York, N.Y., a corporation of New Jersey Filed May 14,1964, Ser. No. 367,419 6 Claims. (Cl. 215-74) This invention relates toclosures for containers such as collapsible tubes, plastic bottles andthe like, and is particularly directed to an improved captive cap typeclosure wherein the cap and container neck which comprise the closureare at all times positively engaged and are prevented from accidentaldislodgment due to excessive twisting.

Captive cap closures are known wherein the threads of the cap remainengaged with the threads of the container neck when the cap is rotatedto its open position. In such arrangements, cooperable beads or similarstop elements on the cap and neck come into locking engagement both tolimit the outward displacement of the cap and, supposedly, to preventits further rotation. A disadvantage of closures of this type is in thefact that the unwary user of the container often applies excessive twistor rotation to the cap beyond that which is necessary to fully open theclosure. This often results in serious damage to the closure, such asthread stripping, which may render it useless, or, the locking beads maybe forced over each other, thereby permitting the cap to becomecompletely dislodged from the neck.

Captive closures also are known which seek to avoid the above problems.One such arrangement provides for total disengagement of the neck andcap threads in the open position of the closure so that the cap, whilestill retained on the neck by the displacement limiting means, is freelyrotatable. A disadvantage of this construction is in the need forre-engaging the threads to close the cap. This requires the user to huntor blindly seek proper reengagement of the threads by trial and error,and frequently leads to thread cocking, damage to the closure andimproper sealing.

A primary object of my present invention is to provide a captive capclosure which both maintains the threads in position for positivere-engagement at all times and enables continued rotation of the cap inits fully open position without dislodgement.

Another object of this invention is to provide a captive cap closureconstruction wherein the cap and neck members comprising the closure arerelatively oonfigurated and dimensioned so that the cooperating threadson the cap and neck are adapted to assume a position of minimumengagement ensuring positive re-engagement at all times and at the sametime permit additional relative rotation without dislodgement of thecap.

These and other objects and advantages of this invention and theirmanner of accomplishment will be apparent from the following descriptionwhich, taken in connection with the accompanying drawing and appendedclaims, discloses a preferred embodiment thereof.

Referring to the drawing:

FIGURE 1 is a vertical view, partly in section, of the closure of thisinvention in closed position;

FIGURE 2 is an enlarged vertical sectional view of the closure in openposition;

FIGURE 3 is a transverse sectional view taken substantially along lines3-3 of FIGURE 2;

FIGURE 4 is a fragmentary sectional view taken substantially along lines44 of FIGURE 3.

FIGURE 5 is an enlarged fragmentary sectional view depicting therelationship of the closure threads as they begin to override uponcontinued rotation of the closure cap when in full open position.

3,263,851 Patented August 2, 1966 FIGURE 6 is an enlarged fragmentarysectional view, similar to FIGURE 4, depicting the closure threads beingdeformed and about to snap over each other after a partial turn of theclosure cap beyond the circumferential position depicted in FIGURE 5.

The drawing illustrates a form of closure having its internal or neckelement formed as an integral part of a container 10, such as a plasticbottle or collapsible tube, although the closure could be a separateunit adapted to be assembled to the discharge end of the container. Asshown, the closure comprises an internal neck generally designated 11and an external captive cap generally designated 24 threadably engagedwith the neck, the two members being permanently locked together bycooperating displacement limiting means adapted to interlock in the openposition of the closure.

Neck 11 has an interior passage 12 communicating with the interior ofcontainer 10, and includes at its upper end a central closure plug 13integrally supported on radiating arms 14 connected to the inner wall ofthe neck, which arms are circumferentially spaced apart to providedischarge apertures 15 surrounding plug 13. The peripheral surface ofthe plug may be tapered as at 16 and is adapted to seat within anaperture of like configuration in cap 24.

The lower end of neck 11 adjacent the container 10 is in the form of aheavy annular section 17 and is formed on its exterior surface with ahelical thread 18, the armate length of which preferably is aboue oneand one-half turns. The upper or lead-in surface 18 of thread 18 isformed at a slightly less than 45 angle to the surface of neck section17, whereas the lower or lead-out surface 18 of the thread is formedslightly less than perpendicular to this surface. The terminal orlead-in end of thread 18 has the form of a rounded run-out segment 18::which extends for a short arcuate distance of the thread length at itsterminal end.

The upper end of neck 11 is formed with an annular peripheral groove 20of predetermined height and an annular peripheral head 21 ofpredetermined diameter defining the upper end wall of groove 20. Thelower end of the groove is defined by a perpendicular wall 22 disposed apredetermined distance above thread 18. The upper surface 23 of the neckis formed with a slightly curved contour to provide sealing engagementwith the captive cap 24, next to be described.

Cap 24 comprises an upper dome-shaped roof or wall 25 having a centraltapered aperture 26 adapted to sealingly engage plug 13 of the neck, alower annular portion 27 having an internal helical thread 28 formedintegrally therewith, and an intermediate annular portion 29 having asmooth interior wall 30 which sealingly engages bead 21 on the neckabove an interior annular head 31 which is adapted to move in neckgroove 20 and abut against the lower surface of head 21 to limit theupper displacement of the cap 24 when the latter is rotated to openposition.

Cap thread 28 is of similar configuration to neck thread 18, beingprovided with a lower or lead-in surface 28 inclined at an angle lessthan 45 to the axis of the cap, an upper or lead-out surface 28 slightlyless than perpendicular to the cap axis, and a rounded, terminal lead-insegment 28a extending a short arcuate length of the thread at theterminal end. The arcuate length of cap thread may but need not be thesame as that of neck thread 18.

To assemble cap 24 on neck 11 of the container, internal cap bead 31 isforced down and deformed over neck head 21 while at the same timethreads 18 and 28 are brought into the readily engageable position shownin FIGURE 4. This is made possible by the fact that neck 11 and/ or cap24 are made of a resilient and deformable material, examples of whichare polyethylene, polypropylene, polyvinyl chloride, polystyrene orother types of synthetic resins. It is not necessary that both the neckand cap be of the same material or possess the same degree ofdeformability and resiliency, so long as the relative dimensions andresiliency and deformability characteristics are such as to provide theintended func tioning. For example, cap 24 may be of a somewhat rigidt-hermosetting material and neck 11 may be of a relatively softer andmore resilient thermoplastic material, or vice versa. Also, it ispossible that one or the other of these two members could be metalhaving very low de'formability, in which case the other member would beof a material possessing the requisite resiliency and deformability topermit the desired assembly and functionmg.

When the closure is assembled and fully closed, as illustrated in FIGURE1, threads 18 and 28 arein a position of maximum engagement withinternal cap bead 31 resting in sealed engagement against the bottomwall 22 of neck groove 20. In this position, the contoured inner surfaceof cap roof 25 also tightly seals against end surface 23 of the neck andtapered aperture 26 seals about tapered plug 16, thus providing acompletely fluidtight closure sealed at three places above the threads.

In the open position of the closure, as illustrated in FIGURE 2, threads18 and 28 are in a position of minimum engagement. By the expressionminimum engagement is meant that the neck and cap threads are either notcompletely disengaged or that the threads assume a relative positionwhere their terminal ends 18a and 28a, respectively, are substantiallycircumferentially aligned (FIGURES 3 and 4), by reason of cap bead 31coming into locking engagement with neck bead 21 above the threads. Thisrelationship is a function of the spacing of the displacement limitingbeads 21 and 31 above the threads as well as the arcuate length andpitch configuration of the threads themselves. As best illustrated inFIGURE 4, terminal end 28a of the cap thread is restrained from furtherupward axial'movement by cap bead 31 abutting against neck bead 21. Atthe same time, cap thread 28 is held down tightly against a lowersegment of neck thread 18. Thus, the threads are retained at alltimes-in engaged contact for quick re-engagement when it is desired toreclose the closure. If desired, the minimum engagement of threads 18and 28 may be as much as a quarter of a turn, for example, in which caseterminal ends 18a and 2811 would be circumferentially displacedapproximately 90 rather than in alignment as illustrated.

While sufficiently deformable to permit cap 24 to be forced onto neck 11in initial assembly of the closure, beads 21 and 31 have the requisitestrength to resist deformation in the open position of the closure toprevent its disassembly. That is, the depth and thickness dimensions ofbeads 21 and 31' and the fact that they are engageable for the fullcircumference of the closure give them a resistance to deformation uponthe opening of the closure to the position of minimum thread engagementsubstantially in excess of the resistance to deforma-' tion of threads18 and 28 to each other, whether slightly engaged or in the positionshown in FIGURES 3 and 4. Thus, the tendency is for these threads toyield and deform first, in the event the user attempts to applyexcessive twist to cap 24, so that they override and remain in positionfor quick engagement at all times. This overriding action is illustratedin FIGURES and 6, first showing cap thread 28 just beginning to overrideneck thread 18 when the cap is turned in the direction of the arrow andthen depicting the relative deformation of these threads upon continuedturning of the cap just before they snap over each other to remainengaged. It will be seen that this overriding action is facilitated bythe angular relation of the lead-in surfaces 18 and 28 of these threads,plus the fact that the rounded end portions 18a and 28a of the threadsprovide even less resistance to deformation. Accordingly, continuedrotation of cap 24 on neck 11 beyond that position illustrated in FIG-URES 3 and 4 will not permit thread end segment 28a to move up and slipout of engageable position due to the restraining force of beads 21 and31; instead, the threads will be caused to override and assume theirposition for quick engagement at all times regardless of the amount ofexcessive twist applied by the user.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description and it will beapparent that various changes may be made in the form, construction, andarrangement of the parts without departing from the spirit and scope ofthe invention or sacrificing all of its material advantages, the'formhereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A closure for a container comprising a hollow neck of resilientdeformable thermoplastic material having a top central closure plug anddischarge passages surrounding said plug, said neck having integralexterior threads and an annular integral bead spaced above said threadsa predetermined distance, and a captive cap having a central aperturecooperable with said plug on said neck, interior integral threadscooperable with the exterior threads on said neck and an interiorintegral annular bead spaced above said cap threads a predetermineddistance cooperable with said neck bead to limit outward displacement ofsaid cap, said threads being in a position of maxim-um engagement whensaid cap is turned down on said neck with said plug sealing saidaperture and in a position of minimum engagement when said cap is turnedup on said neck with said beads in interlocked engagement so that saidthreads engage each other for a small portion of their respectivelengths, said beads and said threads being configurated and relativelydimensioned so that said threads in said position of minimum engagementdeform and override each other and remain in said position of minimumengagement to permit continued rotation of said cap in its open positionwithout disengaging said beads and said cap from said neck.

2. The closure of claim 1 wherein the engagement of said threads intheir position of minimum engagement is approximately one quarter of aturn.

3. The closure of claim 1 wherein the'terminal lead-in ends of saidthreads are substantially circumferentially aligned at the time thebeads initially engage upon opening of the cap.

4. The closure of claim 1 wherein the lead-in surfaces of said threadsare slightly inclined to the axis of said neck and the lead-out surfacesare of substantially greater inclination.

5. The closure of claim 1 wherein the lead-in ends of said threads arerounded. 6. The closure of claim 1 including an annular groove betweenthe threads and bead on said neck, said head on said cap riding in saidgroove and being engageable on the lower wall of said groove in closedposition to limit inward displacement of said cap.

References Cited by the Examiner UNITED STATES PATENTS 1,920,199 8/1933Jesnig 222-521 2,060,622 11/1936 Jones 2l574 2,542,350 2/1951 Paulsen222-499 2,759,643 8/1956 Dahlin 222--521 THERON E. CONDON, PrimaryExaminer.

v JOSEPH R. LECLAIR, Examiner.

1. A CLOSURE FOR A CONTAINER COMPRISING A HOLLOW NECK OF RESILIENT DEFORMABLE THERMOPLASTIC MATERIAL HAVING A TOP CENTRAL CLOSURE PLUG AND DISCHARGE PASSAGES SURROUNDING SAID PLUG SAID NECK HAVING INTEGRAL EXTERIOR THREADS AND AN ANNULAR INTEGRAL BEAD SPACED ABOVE SAID THREADS A PREDETERMINED DISTANCE, AND A CAPTIVE CAP HAVING A CENTRAL APERTURE COOPERABLE WITH SAID PLUG ON SAID NECK, INTERIOR INTEGRAL THREADS COOPERABLE WITH THE EXTERIOR THREADS ON SAID NECK AND AN INTERIOR INTEGRAL ANNULAR BEAD SPACED ABOVE SAID CAP THREADS A PREDETERMINED DISTANCE COOPERABLE WITH SAID NECK BEAD TO LIMIT OUTWARD DISPLACEMENT OF SAID CAP, SAID THREADS BEING IN A POSITION OF MAXIMUM ENGAGEMENT WHEN SAID CAP IS TURNED DOWN ON SAID NECK WITH SAID PLUG SEALING SAID APERTURE AND IN A POSITION OF MINIMUM ENGAGEMENT WHEN SAID CAP IS TURNED UP ON SAID NECK WITH SAID BEADS IN INTERLOCKED ENGAGEMENT SO THAT SAID THREADS ENGAGE EACH OTHER FOR A SMALL PORTION OF THEIR RESPECTIVE LENGTHS, SAID BEADS AND SAID THREADS BEING CONFIGURATED AND RELATIVELY DIMENSIONED SO THAT SAID THREADS IN SAID POSITION OF MINIMUM ENGAGEMENT DEFORM AND OVERRIDE EACH OTHER AND REMAIN IN SAID POSITION OF MINIMUM ENGAGEMENT TO PERMIT CONTINUED ROTATION OF SAID CAP IN ITS OPEN POSITION WITHOUT DISENGAGING SAID BEADS AND SAID CAP FROM SAID NECK. 